What they’re good for
- Odor & nuisance monitoring. MSW releases a mix of VOCs whose levels rise with time, temperature, and composition. Tracking TVOC at bins, in truck hoppers, and at transfer‑station fencelines helps localize issues and correlate with complaints. Electronic‑nose studies and reviews support landfill/plant odor monitoring and quantification models (Ratti 2024; Lotesoriere 2024; Hassan 2025; Jońca 2022).
- Smart bins & routing. VOC trends can complement fill‑level to prioritize pickups and flag mis‑sorted streams; many smart‑bin designs include an odor/VOC channel (Polimi thesis; smart‑bin paper; comparative study).
- Worker exposure screening. PIDs provide rapid, semi‑quantitative screening for VOCs during spills or at transfer stations; agencies position them as field screening tools (see NIOSH NMAM, Alaska DEC 2024 field guidance, EPA ESA Ch.6).
- Contamination & source‑separation QA. Solvent‑like spikes often indicate paint/solvent contamination in recycling or organics streams; e‑noses and chemical sensors are documented in waste‑sector QA (Wiśniewska 2021).
- Early fire‑risk cues. Battery‑related fires in trucks and facilities are a growing hazard; pre‑ignition off‑gassing often includes organics. Rising TVOC (with temperature/CO) can prompt SOPs to isolate/dump safely (US EPA report; EPA Li‑ion guidance).
Sensor options
| Type | What it measures | Strengths | Limitations | Good refs |
|---|---|---|---|---|
| PID (photoionization detector) | TVOC (ppb–ppm). Aromatics/solvents respond strongly. | Fast, sensitive, well‑established for field screening. | Not compound‑specific; response depends on lamp energy & response factors; 10.6 eV PIDs do not detect methane. | RAE PID Handbook; Ion Science (PID vs FID); PID RF chart |
| MOS “e‑nose” array | Pattern/fingerprint of VOC mixtures (odor index) | Low‑cost, low‑power; learn odor signatures for bins/fenceline. | Needs training/ML; humidity/temperature compensation. | Ratti 2024; Lotesoriere 2024; Jońca 2022 |
| Complementary CH4 (NDIR) | Methane (LEL–%vol) | Selective and robust; independent of O2. | Not a general VOC sensor. | Edinburgh Sensors; Cubic SJH series |
| Complementary H2S (electrochemical) | Hydrogen sulfide (odor/toxicity) | Target‑specific; common in waste/WWTP. | Requires periodic calibration/bump tests. | Honeywell CityTech; Emerson Rosemount |
Tip: For natural‑gas leaks in the load, use FID or NDIR‑CH4 because standard 10.6 eV PIDs don’t see methane (Ion Science).
How to deploy
On‑truck monitoring
Sample hopper headspace with a small pump to a rugged PID; log TVOC with GPS, time, ambient T/RH, and compactor state. Alarm on steep deltas; pair with CO and temperature to reduce false positives. Use field‑screening practices from H&S manuals (NIOSH NMAM; Alaska DEC 2024).
Smart‑bin nodes
Combine fill‑level (ultrasonic/vision) + MOS TVOC + T/RH. Use thresholds and simple models to escalate pickups for organics or flag likely contamination (Polimi thesis; comparative study).
Fenceline / transfer station
Networked e‑nose nodes plus meteorology for real‑time odor indices and complaint correlation; recent papers demonstrate classification/quantification workflows (Ratti 2024; Lotesoriere 2024). For fire‑risk awareness, incorporate temperature/CO and track VOC trends; see battery‑fire risk context (US EPA report).
Caveats & good practice
- Cross‑sensitivities & drift. VOC sensors respond to humidity/temperature and mixtures—apply RH/T compensation, regular calibration and lamp maintenance for PIDs (RAE Handbook; Van Walt tech note).
- Right tool for the gas. Use NDIR for CH4 and electrochemical for H2S; reserve PIDs/e‑noses for general organics (Ion Science; Edinburgh Sensors).
- Data context matters. VOC baselines vary by season, route, and waste mix; trend data and pair with operational context (fill‑level, temperature, route logs).
Sources (selected)
- RAE Systems PID Handbook • Honeywell/RAE PID User Guide.
- Ion Science: PID vs FID (methane not detected by 10.6 eV PID) • PID response factor chart.
- NIOSH Manual of Analytical Methods (5th ed.) • Alaska DEC 2024 Field Sampling Guidance • EPA ESA Chapter 6.
- Electronic‑nose & odor monitoring: Ratti 2024 • Lotesoriere 2024 • Hassan 2025 • Jońca 2022.
- Smart‑bin literature: Polimi smart‑bin thesis • Brouwer 2023.
- Complementary gas sensing: CH4 (NDIR) Edinburgh Sensors • Cubic SJH; H2S (electrochemical) Honeywell CityTech • Emerson Rosemount.
- Fire‑risk context: US EPA: Lithium‑ion battery fires in waste & recycling • EPA: Lithium‑ion battery recycling & hazards.